Looper-thread-controlling mechanism for sewing-machines.



, B. V. KERSHNER. LOOPER THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED OCT. 21, 1915.

Patented Nov. 19, 1918.

4 SHEETS-SHEEI I.

B. V. KERSHNER. LOOPER THREAD CONTROLLING MECHANISM FOR SEWING MACHINES. APPLICATION FILED 061227. 19x5.

1,285,219. Patnted Nov. 19, 1918.

4 SHEETS-SHEEI 2.

B. V. KERSHNER. LOOPER THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

' APPLICATION FILED OCT. 21. 1915- 1,285,21 9. Patented Nov. 19, 1918.

4 SHEETSSHEEI 3.

B. V. KERSHNER. LOOPER THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

. APPLICATION FILED OCT. 27; I915, 1,285,21 9. Patented Nov. 19, 1918.

4 SHEETS-SHEEI 4.

' F'Qig,

a 6 a CL 2 I 4 Z2 UNITED srn'rns PATENT OFFICE.

BENJAMIN V. KERSHNER, OF BOSTON, MASSACHUSETTS, ASSIGIFOR TO UNION SPECIAL .IMIACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

LOOPERr-THBEAD-CONTROLLING MECHANISM FOR SEWING-MACHINES.

' Specification of Letters Patent.

Patented Nov. 19, .1918.

Application filed October 27, 1915. 2 Serial No. 58,148.

To all whom it may concern:

Be it known that I, BENJAMIN V. KERS'H- NER, a citizen of the United States, residing at Boston, in the county of Suffolk, State of Massachusetts, have invented certain new and useful Improvements in Trooper-Thread- Controlling Mechanism for Sewing-Machines, of which the following is a description, reference being had to the accompanying drawing and to the figures ofreference marked thereon. v

This invention relates-to new and useful improvements in looper thread controlling mechanisms for sewing machines, and more particularly to the thread controlling mechanism wherein a rotating member takes up and releases the looper thread.

An object of the invention is to provide a looper thread controlling mechanism wherein a rotating controlling cam 006perates with thread guides for taking up and releasing the looper thread, with an adjustable releasing finger for releasing the thread on the take-up cam and with anadjustable retaining finger for retaining the thread after it is released, whereby the time of releasing and consequently the amount of thread taken up Fig. 2 is a view, partly in plan and partly in section, showing a looper thread controlling mechanism having my improvements applied thereto;

Fig. 3 is a' vertical sectional view through the bed plate, showing in side elevation the controlling cam, the thread guides c'o6perat-' ing therewith, the take-up or-"releasing finger, and the check or retaining finger which cooperates with said cam;

Fig. 4 is a detail in perspective showing the take-up finger and the retaining finger and the means for supporting the same;

Fig. 5 is a sectional view showing the manner of supporting the take-up finger,

also showing in side elevation the retaining Fig. 6 'is a sectional view showing a modified form of means for supporting the takep finger;

Fig. 7 is a view, partly in section and partly in side elevation, showing the take up cam and the controlling fingers therefor, with the take-up cam in position for initial engagement with the looper thread;

Fig. 8 is a similar view showing the takeup cam rotated to bring the looper thread into engagement with the take-up finger;

Flg. 9 is a similar view showing the looper thread released from the take-up shoulder of the cam by said take-up or release finger, and the retaining or check finger as holding the thread; and

Fig. 10 is a similar view showing the takeup cam rotated so as to release the thread from said check or retaining finger.

In the drawings, I have shown my 'in- 'vention applied to a sewing machine conlever is oscillated by a suitable eccentric on the main shaft, through an eccentric strap 9 pivoted at 10 to the needle lever.

Mounted on the bed plate 1 is a work support 11 having feed slots 12 through'which the feed dog 13 operates. Cooperating with the needle beneath the work support is a looper 14, the looper being pivotally mounted on a looper support and moved into and out of the needle loop by a link 15 which is pivoted at 16 to the needle lever extension 17 The looper thread 1 is led from the supply through a suitable thread guide 18 and passed through a tension 19 to spaced thread.

guides 20 20. Cooperating with the thread guides 2020 is a suitable pull-off 21. After leaving the thread guides 2020, the looper thread passes through nippers 22, and thence to the spaced threadguides 23 23. Cooperating with the spaced thread guides 2323 is a rotatingta'ke-up cam 24 having the usual central groove 25. The take-up cam 24 is mounted on the main shaft 26 and rotates therewith. The thread passes from the thread gnide 23 at the left of the take-up cam, as viewed in Fig. 2, to the looper 14:.

Coia'perating with the take-up cam 2a is a take-up finger 26. This take-up finger 26 'is mounted in a bracket 27 and extends outthread-engaging surface I) which gives up rapidly.

and thence an eccentric the thread gradually,

the thread very surface at which gives up Also mounted on the bracket 27 is a retaining or check finger 28. As the cam 2 1 rotates, the cam shoulder a engages the thread running through the thread guides 23 and carries the same along, as indicated in Fig. 8 of the drawings. The thread is brought into engagement with this take-up finger 26, and when the cam reaches the position shown in Fig. 9, the thread will be released from the cam shoulder a and will be caught by the check or retaining finger 28, as shown in this figure. A further rotation of the cam brings the eccentri surface 0 underneath the retaining or check finger 28, and the looper thread will then be released so that it will be held solely by the eccentric surface 0 of the take-up cam. Further movement of the take-up cam releases the thread from this surface 0 onto the surface at of the take-up cam.

The take-up finger 26" shank 29, which extends downwardly through an opening 30 in the bracket 27. A clamping screw 31 carried by the bracket is adapted to be set up against this shank and hold the take-up finger in an adjusted position. Viewing the parts as positioned in Fig. 9, it will be readily apparent that, it this take-up finger 26 is raised, the point of releasing the thread will occur earlier in the time of rotation of the take-up cam 24, while,

if the take-up finger is lowered, then the time of release will occur at a later period in the rotation of the cam.

The check. finger 28 has a downwardly extending shank 32 which is bent horizontally, forming a horizontal section 33. This horizontal section of finger extends through an opening in the bracket 27, and a set-screw 3 carried by the bracket engages the shank and holds the retaining finger against movement. By loosening this screw, it will be apparent that the retaining finger may be adjusted horiis carried by a sleek given up to derstood that in a l the retaining or check rea ers zontally so which coiiperates with the take-up cam, may be moved either to the right or to the left, as viewed in Fig. 3.

When the thread is released from the cam shoulder a, it will be caught by the retaining or check finger 28 and the amount of therefore, depends upon the distance between this retaining or check finger 28 and the cam shoulder when releasing the thread. By adjusting this retaining or check finger 28 -to the right, as viewed in Fig. 9, more slack will be given to the thread, and by adjusting the same to the left, then less slack will be given to the loo er thread. It will be unpositions of adjustment of the finger 28, the depending nose 28 thereof extends beneath the concentric surface I) of the take-up cam er.

in Fig. 6 of the drawings, a modified supporting means I have shown for the retaining finger. The shank 32 forthe retaining finger 28 is vertical throughout and extends through an opening 35 in a support 36 carried b the bracket 27. This support has a threa ed shank 37 carrying a threaded sleeve 38 which bears against the outerrface of the bracket. There are two adjustable abutment screws 39 and 4.0 which are threaded through the supporting bracket 27 By shifting the support through the turning of the sleeve 38, the shank of the same is clamped against these abutments 39 and 40. By shiftin the position of the abutments 39 and 40, relative to each other, or relative to the shank, various taining finger may be taining finger may be shifted either to the right or to the left as viewed in Fig. 3, and may also be slightly tilted so as to maintain the nose of the retaining finger a uniform distance beneath the concentric surface 6 or the take-up cam 24.

The operation of the needle and the looper in this type ofmachine is well understood. The looper moves forward into the needle loop to the end of its stroke, after which it is shifted laterally and then retracted. The needle on its next descent passes between the needle loop, the looper, and the looper thread, after which the looper is retracted from the previous needle loop, and the retracting movement or the looper, together made so that said rewith the downward movement of the needle that the extreme end thereof,

the looper at this time,

adjustments of the re- 7 I the looper will pass the needle at a proper time. The shifting of the looper so that it moves to a greater distance away from the path of the needle requires that more slack thread be given to the looper as it is reaching the rear end of its stroke. By adjusting the retaining or check finger 28, the amount of slack given to the looper thread may be regulated to correspond with the setting of the looper. By my improved means of su porting the take-up finger, it may be quic y adjusted and set so as to properly coiiperate with the take-up cam. By raising the takeup finger, the time of releasing the thread will be slightly advanced, and by lowering the take-up finger, vthe time of release will be retarded. As soon as the thread is re leased from this eccentric surface a of the take-up cam, it is drawn against the retaining or check finger 28, and the position of this check finger determines the amount of slack given to the looper thread. By my improved means, therefore, of mounting the take-up finger and the retaining finger, I am able to vary the time of release of the thread by the take-up finger, and the amount of slack retained by the retaining finger, so that thethread controllingmechanism may be quickly adjusted to properly operate on the looper thread,

It is obvious that minor changes in the details of construction and the arrangement of parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what is claimed as new and desired to secure by Letters-Patent is 1. The combination with a take-up cam, a take-up finger for releasin the thread from the take-up cam, a retaining finger for .retaining the thread when released from the take-up cam, means for supporting the takeup finger, whereby the same maybe adjusted for varying the time of release of the thread, and means for supporting the retaining finger, whereby the same maybe adjusted independently of the take-up finger for varying the amount of slack in the thread held thereby.

2. The combination with a work support, a needle, a thread-carrying looper coiiperating with the needle beneath the Work support, a looper thread controlling mechanism including thread guides, a rotating take-up cam having a thread-engaging'shoulder for engaging the thread between said guides, a take-up finger for releasing the thread from the cam shoulder, a retaining finger for retaining the thread when released from the cam shoulder, and means for supporting the take-up finger whereby it may be adjusted independently of the retaining finger.

3. The combination with a work support, a needle, a thread-carrying looper cooperating with the needle beneath the work support, a looper thread controlling mechanism including thread guides, a rotating take-up cam having a thread-engaging shoulder for engaging the thread between said guides, a

take-up finger for releasing the thread from the cam shoulder, a retaining finger for retaining the thread when released from the cam shoulder, and. means for supporting said retaining finger, whereby it may be adjusted independently of said take-up finger.

4. The combination with a work support, a needle, and a thread carrying looper cooperating with the needle beneath the work support, of a looper thread controlling mechanism including thread guides for the looper thread, a rotating take-up cam for engaging the looper thread between said guides, said take-up cam having an eccentric thread engaging surface and a concentric thread engaging surface, a take-up finger cooperating with said take-up cam for releasin the looper thread from said eccentric sur ace, means for supporting the takeup finger whereby the same may be adjusted for varying the time of release of the looper thread and means for supporting the retaining finger whereby the same may be adjusted independently of the take-up finger for varying the amount of slack in the looper thread held thereby.

In testimony whereof, I afiix my signature in the presence of two Witnesses.

BENJAMIN V. KERSHNER.

Witnesses:

CHARLES L. STURrnvAN'r,

REUBEN Ourronn PRA'I'I. 

